/* Includes ------------------------------------------------------------------*/
#include "eeprom.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

/* Global variable used to store variable value in read sequence */
uint32_t DataVar = 0;

/* Virtual address defined by the user: 0xFFFF value is prohibited */


/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
static FLASH_Status EE_Format(void);
static uint16_t EE_FindValidPage(uint8_t Operation);
static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint32_t Data);
static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint32_t Data);




static FLASH_Status FLASH_ErasePage(uint32_t Page_Address) {
    uint8_t i;
    uint8_t sector_num;
    
    sector_num = (uint8_t)(PAGE_SIZE / FLASH_SECTOR_SIZE);
    
    for (i = 0; i < sector_num; i ++) {
        if (FL_FAIL == FL_FLASH_SectorErase(FLASH, Page_Address + i * FLASH_SECTOR_SIZE)) {
            return FLASH_BUSY;
        }
    }
    return FLASH_COMPLETE;
}

static FLASH_Status FLASH_ProgramHalfWord(uint32_t Address, uint32_t Data) {
    if (FL_FAIL == FL_FLASH_Program_Word(FLASH, Address, Data)) {
        return FLASH_BUSY;
    } else {
        return FLASH_COMPLETE;
    }
}

/**
  * @brief  Restore the pages to a known good state in case of page's status
  *   corruption after a power loss.
  * @param  None.
  * @retval - Flash error code: on write Flash error
  *         - FLASH_COMPLETE: on success
  */
uint16_t EE_Init(void) {
    uint16_t PageStatus0, PageStatus1;
    uint16_t VarIdx = 0;
    uint16_t EepromStatus = 0, ReadStatus = 0;
    int16_t x = -1;
    uint16_t  FlashStatus;
    
    /* Get Page0 status */
    PageStatus0 = (*(__IO flashOperation_t *)PAGE0_BASE_ADDRESS);
    /* Get Page1 status */
    PageStatus1 = (*(__IO flashOperation_t *)PAGE1_BASE_ADDRESS);
    
    /* Check for invalid header states and repair if necessary */
    switch (PageStatus0) {
        case ERASED:
            if (PageStatus1 == VALID_PAGE) { /* Page0 erased, Page1 valid */
                /* Erase Page0 */
                FlashStatus = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else if (PageStatus1 == RECEIVE_DATA) { /* Page0 erased, Page1 receive */
                /* Erase Page0 */
                FlashStatus = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
                /* Mark Page1 as valid */
                FlashStatus = FLASH_ProgramHalfWord(PAGE1_BASE_ADDRESS, VALID_PAGE);
                /* If program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else { /* First EEPROM access (Page0&1 are erased) or invalid state -> format EEPROM */
                /* Erase both Page0 and Page1 and set Page0 as valid page */
                FlashStatus = EE_Format();
                /* If erase/program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            }
            break;
            
        case RECEIVE_DATA:
            if (PageStatus1 == VALID_PAGE) { /* Page0 receive, Page1 valid */
                /* Transfer data from Page1 to Page0 */
                for (VarIdx = 0; VarIdx < NumbOfVar; VarIdx++) {
                    if ((*(__IO flashOperation_t *)(PAGE0_BASE_ADDRESS + PAGE_FIRST_VARIABLE_ADDRESS)) == VarIdx) {
                        x = VarIdx;
                    }
                    if (VarIdx != x) {
                        /* Read the last variables' updates */
                        ReadStatus = EE_ReadVariable(VarIdx, &DataVar);
                        /* In case variable corresponding to the virtual address was found */
                        if (ReadStatus != 0x1) {
                            /* Transfer the variable to the Page0 */
                            EepromStatus = EE_VerifyPageFullWriteVariable(VarIdx, DataVar);
                            /* If program operation was failed, a Flash error code is returned */
                            if (EepromStatus != FLASH_COMPLETE) {
                                return EepromStatus;
                            }
                        }
                    }
                }
                /* Mark Page0 as valid */
                FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
                /* If program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
                /* Erase Page1 */
                FlashStatus = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else if (PageStatus1 == ERASED) { /* Page0 receive, Page1 erased */
                /* Erase Page1 */
                FlashStatus = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
                /* Mark Page0 as valid */
                FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
                /* If program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else { /* Invalid state -> format eeprom */
                /* Erase both Page0 and Page1 and set Page0 as valid page */
                FlashStatus = EE_Format();
                /* If erase/program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            }
            break;
            
        case VALID_PAGE:
            if (PageStatus1 == VALID_PAGE) { /* Invalid state -> format eeprom */
                /* Erase both Page0 and Page1 and set Page0 as valid page */
                FlashStatus = EE_Format();
                /* If erase/program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else if (PageStatus1 == ERASED) { /* Page0 valid, Page1 erased */
                /* Erase Page1 */
                FlashStatus = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            } else { /* Page0 valid, Page1 receive */
                /* Transfer data from Page0 to Page1 */
                for (VarIdx = 0; VarIdx < NumbOfVar; VarIdx++) {
                    if ((*(__IO flashOperation_t *)(PAGE0_BASE_ADDRESS + PAGE_FIRST_VARIABLE_ADDRESS)) == VarIdx) {
                        x = VarIdx;
                    }
                    if (VarIdx != x) {
                        /* Read the last variables' updates */
                        ReadStatus = EE_ReadVariable(VarIdx, &DataVar);
                        /* In case variable corresponding to the virtual address was found */
                        if (ReadStatus != 0x1) {
                            /* Transfer the variable to the Page1 */
                            EepromStatus = EE_VerifyPageFullWriteVariable(VarIdx, DataVar);
                            /* If program operation was failed, a Flash error code is returned */
                            if (EepromStatus != FLASH_COMPLETE) {
                                return EepromStatus;
                            }
                        }
                    }
                }
                /* Mark Page1 as valid */
                FlashStatus = FLASH_ProgramHalfWord(PAGE1_BASE_ADDRESS, VALID_PAGE);
                /* If program operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
                /* Erase Page0 */
                FlashStatus = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
                /* If erase operation was failed, a Flash error code is returned */
                if (FlashStatus != FLASH_COMPLETE) {
                    return FlashStatus;
                }
            }
            break;
            
        default:  /* Any other state -> format eeprom */
            /* Erase both Page0 and Page1 and set Page0 as valid page */
            FlashStatus = EE_Format();
            /* If erase/program operation was failed, a Flash error code is returned */
            if (FlashStatus != FLASH_COMPLETE) {
                return FlashStatus;
            }
            break;
    }
    
    return FLASH_COMPLETE;
}

/**
  * @brief  Returns the last stored variable data, if found, which correspond to
  *   the passed virtual address
  * @param  VirtAddress: Variable virtual address
  * @param  Data: Global variable contains the read variable value
  * @retval Success or error status:
  *           - 0: if variable was found
  *           - 1: if the variable was not found
  *           - NO_VALID_PAGE: if no valid page was found.
  */
/* -----------------------------------------------------------------------A12
写入一个EE虚拟地址，读出32bit数据
----------------------------------------------------------------------- */
uint16_t EE_ReadVariable(uint16_t VirtAddress, uint32_t *Data) {
    uint16_t ValidPage = PAGE0;
    uint16_t AddressValue = 0x5555, ReadStatus = 1;
    uint32_t Address, PageStartAddress;
    
    /* Get active Page for read operation */
    ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
    
    /* Check if there is no valid page */
    if (ValidPage == NO_VALID_PAGE) {
        return  NO_VALID_PAGE;
    }
    
    /* Get the valid Page start Address */
    PageStartAddress = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
    
    /* Get the valid Page end Address */
    Address = (uint32_t)((EEPROM_START_ADDRESS - FLASH_OPERATION_LEN) + (uint32_t)((1 + ValidPage) * PAGE_SIZE));
    
    /* Check each active page address starting from end */
    while (Address > (PageStartAddress + FLASH_OPERATION_LEN)) {
        /* Get the current location content to be compared with virtual address */
        AddressValue = (*(__IO flashOperation_t *)Address);
        
        /* Compare the read address with the virtual address */
        if (AddressValue == VirtAddress) {
            /* Get content of Address-FLASH_OPERATION_LEN which is variable value */
            *Data = (*(__IO flashOperation_t *)(Address - FLASH_OPERATION_LEN));
            
            /* In case variable value is read, reset ReadStatus flag */
            ReadStatus = 0;
            
            break;
        } else {
            /* Next address location */
            Address = Address - ELEMENT_LEN;
        }
    }
    
    /* Return ReadStatus value: (0: variable exist, 1: variable doesn't exist) */
    return ReadStatus;
}

/**
  * @brief  Writes/upadtes variable data in EEPROM.
  * @param  VirtAddress: Variable virtual address
  * @param  Data: 16 bit data to be written
  * @retval Success or error status:
  *           - FLASH_COMPLETE: on success
  *           - PAGE_FULL: if valid page is full
  *           - NO_VALID_PAGE: if no valid page was found
  *           - Flash error code: on write Flash error
  */
/* -----------------------------------------------------------------------A12
写入一个EE虚拟地址和32bit数据
----------------------------------------------------------------------- */
uint16_t EE_WriteVariable(uint16_t VirtAddress, uint32_t Data) {
    uint16_t Status = 0;
    
    /* Write the variable virtual address and value in the EEPROM */
    Status = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
    
    /* In case the EEPROM active page is full */
    if (Status == PAGE_FULL) {
        /* Perform Page transfer */
        Status = EE_PageTransfer(VirtAddress, Data);
    }
    
    /* Return last operation status */
    return Status;
}

/**
  * @brief  Erases PAGE0 and PAGE1 and writes VALID_PAGE header to PAGE0
  * @param  None
  * @retval Status of the last operation (Flash write or erase) done during
  *         EEPROM formating
  */
static FLASH_Status EE_Format(void) {
    FLASH_Status FlashStatus = FLASH_COMPLETE;
    
    /* Erase Page0 */
    FlashStatus = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
    
    /* If erase operation was failed, a Flash error code is returned */
    if (FlashStatus != FLASH_COMPLETE) {
        return FlashStatus;
    }
    
    /* Set Page0 as valid page: Write VALID_PAGE at Page0 base address */
    FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
    
    /* If program operation was failed, a Flash error code is returned */
    if (FlashStatus != FLASH_COMPLETE) {
        return FlashStatus;
    }
    
    /* Erase Page1 */
    FlashStatus = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
    
    /* Return Page1 erase operation status */
    return FlashStatus;
}

/**
  * @brief  Find valid Page for write or read operation
  * @param  Operation: operation to achieve on the valid page.
  *   This parameter can be one of the following values:
  *     @arg READ_FROM_VALID_PAGE: read operation from valid page
  *     @arg WRITE_IN_VALID_PAGE: write operation from valid page
  * @retval Valid page number (PAGE0 or PAGE1) or NO_VALID_PAGE in case
  *   of no valid page was found
  */
static uint16_t EE_FindValidPage(uint8_t Operation) {
    uint16_t PageStatus0, PageStatus1;
    
    /* Get Page0 actual status */
    PageStatus0 = (*(__IO flashOperation_t *)PAGE0_BASE_ADDRESS);
    
    /* Get Page1 actual status */
    PageStatus1 = (*(__IO flashOperation_t *)PAGE1_BASE_ADDRESS);
    
    /* Write or read operation */
    switch (Operation) {
        case WRITE_IN_VALID_PAGE:   /* ---- Write operation ---- */
            if (PageStatus1 == VALID_PAGE) {
                /* Page0 receiving data */
                if (PageStatus0 == RECEIVE_DATA) {
                    return PAGE0;         /* Page0 valid */
                } else {
                    return PAGE1;         /* Page1 valid */
                }
            } else if (PageStatus0 == VALID_PAGE) {
                /* Page1 receiving data */
                if (PageStatus1 == RECEIVE_DATA) {
                    return PAGE1;         /* Page1 valid */
                } else {
                    return PAGE0;         /* Page0 valid */
                }
            } else {
                return NO_VALID_PAGE;   /* No valid Page */
            }
            
        case READ_FROM_VALID_PAGE:  /* ---- Read operation ---- */
            if (PageStatus0 == VALID_PAGE) {
                return PAGE0;           /* Page0 valid */
            } else if (PageStatus1 == VALID_PAGE) {
                return PAGE1;           /* Page1 valid */
            } else {
                return NO_VALID_PAGE ;  /* No valid Page */
            }
            
        default:
            return PAGE0;             /* Page0 valid */
    }
}

/**
  * @brief  Verify if active page is full and Writes variable in EEPROM.
  * @param  VirtAddress: 16 bit virtual address of the variable
  * @param  Data: 16 bit data to be written as variable value
  * @retval Success or error status:
  *           - FLASH_COMPLETE: on success
  *           - PAGE_FULL: if valid page is full
  *           - NO_VALID_PAGE: if no valid page was found
  *           - Flash error code: on write Flash error
  */
static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint32_t Data) {
    FLASH_Status FlashStatus = FLASH_COMPLETE;
    uint16_t ValidPage = PAGE0;
    uint32_t Address, PageEndAddress;
    
    /* Get valid Page for write operation */
    ValidPage = EE_FindValidPage(WRITE_IN_VALID_PAGE);
    
    /* Check if there is no valid page */
    if (ValidPage == NO_VALID_PAGE) {
        return  NO_VALID_PAGE;
    }
    
    /* Get the valid Page start Address */
    Address = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
    
    /* Get the valid Page end Address */
    PageEndAddress = (uint32_t)((EEPROM_START_ADDRESS - FLASH_OPERATION_LEN) + (uint32_t)((1 + ValidPage) * PAGE_SIZE));
    
    /* Check each active page address starting from begining */
    while (Address < PageEndAddress) {
        /* Verify if Address and Address+FLASH_OPERATION_LEN contents are all 0xF */
        #if (FLASH_OPERATION_LEN == 2)
        if ((*(__IO flashOperation_t *)Address) == 0xFFFFFFFF)
        #elif (FLASH_OPERATION_LEN == 4)
        if (((*(__IO flashOperation_t *)Address) == 0xFFFFFFFF) &&
            ((*(__IO flashOperation_t *)(Address + FLASH_OPERATION_LEN)) == 0xFFFFFFFF))
        #endif
        {
            /* Set variable data */
            FlashStatus = FLASH_ProgramHalfWord(Address, Data);
            /* If program operation was failed, a Flash error code is returned */
            if (FlashStatus != FLASH_COMPLETE) {
                return FlashStatus;
            }
            /* Set variable virtual address */
            FlashStatus = FLASH_ProgramHalfWord(Address + FLASH_OPERATION_LEN, VirtAddress);
            /* Return program operation status */
            return FlashStatus;
        } else {
            /* Next address location */
            Address = Address + ELEMENT_LEN;
        }
    }
    
    /* Return PAGE_FULL in case the valid page is full */
    return PAGE_FULL;
}

/**
  * @brief  Transfers last updated variables data from the full Page to
  *   an empty one.
  * @param  VirtAddress: 16 bit virtual address of the variable
  * @param  Data: 16 bit data to be written as variable value
  * @retval Success or error status:
  *           - FLASH_COMPLETE: on success
  *           - PAGE_FULL: if valid page is full
  *           - NO_VALID_PAGE: if no valid page was found
  *           - Flash error code: on write Flash error
  */
static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint32_t Data) {
    FLASH_Status FlashStatus = FLASH_COMPLETE;
    uint32_t NewPageAddress, OldPageAddress;
    uint16_t ValidPage = PAGE0, VarIdx = 0;
    uint16_t EepromStatus = 0, ReadStatus = 0;
    
    /* Get active Page for read operation */
    ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
    
    if (ValidPage == PAGE1) {     /* Page1 valid */
        /* New page address where variable will be moved to */
        NewPageAddress = PAGE0_BASE_ADDRESS;
        
        /* Old page address where variable will be taken from */
        OldPageAddress = PAGE1_BASE_ADDRESS;
    } else if (ValidPage == PAGE0) { /* Page0 valid */
        /* New page address where variable will be moved to */
        NewPageAddress = PAGE1_BASE_ADDRESS;
        
        /* Old page address where variable will be taken from */
        OldPageAddress = PAGE0_BASE_ADDRESS;
    } else {
        return NO_VALID_PAGE;       /* No valid Page */
    }
    
    /* Set the new Page status to RECEIVE_DATA status */
    FlashStatus = FLASH_ProgramHalfWord(NewPageAddress, RECEIVE_DATA);
    /* If program operation was failed, a Flash error code is returned */
    if (FlashStatus != FLASH_COMPLETE) {
        return FlashStatus;
    }
    
    /* Write the variable passed as parameter in the new active page */
    EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
    /* If program operation was failed, a Flash error code is returned */
    if (EepromStatus != FLASH_COMPLETE) {
        return EepromStatus;
    }
    
    /* Transfer process: transfer variables from old to the new active page */
    for (VarIdx = 0; VarIdx < NumbOfVar; VarIdx++) {
        if (VarIdx != VirtAddress) { /* Check each variable except the one passed as parameter */
            /* Read the other last variable updates */
            ReadStatus = EE_ReadVariable(VarIdx, &DataVar);
            /* In case variable corresponding to the virtual address was found */
            if (ReadStatus != 0x1) {
                /* Transfer the variable to the new active page */
                EepromStatus = EE_VerifyPageFullWriteVariable(VarIdx, DataVar);
                /* If program operation was failed, a Flash error code is returned */
                if (EepromStatus != FLASH_COMPLETE) {
                    return EepromStatus;
                }
            }
        }
    }
    
    /* Erase the old Page: Set old Page status to ERASED status */
    FlashStatus = FLASH_ErasePage(OldPageAddress);
    /* If erase operation was failed, a Flash error code is returned */
    if (FlashStatus != FLASH_COMPLETE) {
        return FlashStatus;
    }
    
    /* Set new Page status to VALID_PAGE status */
    FlashStatus = FLASH_ProgramHalfWord(NewPageAddress, VALID_PAGE);
    /* If program operation was failed, a Flash error code is returned */
    if (FlashStatus != FLASH_COMPLETE) {
        return FlashStatus;
    }
    
    /* Return last operation flash status */
    return FlashStatus;
}



/*********************************END OF FILE**********************************/
